Experimental limits on quantum decoherence from $B$ meson systems

TL;DR

This paper investigates quantum decoherence effects in neutral B-meson systems, providing the first combined analysis for B_d and experimental constraints for B_s, revealing significant non-zero decoherence parameters.

Contribution

It presents the first combined analysis of mixing and CP asymmetry in B_d-mesons and establishes the first experimental constraints on decoherence in B_s-mesons.

Findings

Non-zero value of λ_d at approximately 6σ

Non-zero value of λ_s at 3σ

Constraints on decoherence effects in B-meson systems

Abstract

Neutral $B$-meson systems serve as critical tests of the Standard Model and play a key role in limiting its extensions. While these systems are typically studied under the assumption of perfect quantum coherence, interactions with the environment can lead to decoherence. Such decoherence effects can obscure the measured values of key parameters such as the oscillation frequency $ \Delta m $ and $CP$-violating parameter $ \sin 2\beta $. Using the experimental data, we present the first combined analysis of mixing asymmetry and $CP$-asymmetry measurements for $ B_d $-mesons, which indicates that $ \lambda_d $ is non-zero at approximately $ 6 \,\sigma $. We also establish the first experimental constraints on the decoherence parameter $ \lambda_s $ for $ B_s $-mesons, finding it to be non-zero at $ 3 \,\sigma $.